Improvement in gbinding-mills



G. W. HUBBARD & s. A. SMITH.

GRINDING MILL.

Patented Mar. 10, 1868.

I I a Mi'nesscs #M gums" fates gaunt ffim.

enonen W. HUBBARD. AND scorn A QSMl'FH, 0F PHILADELPHIA, P N SYLVANIA,ASSIGNORSTO cninsson '& SMITH, or SAME PLACE.

Letters Patent No. 75,273,- dated March 10, 18681 IMBROllEMINTINGRINDING-MILLS.

IO-ALL WHOM' IT MAY CONCERN Be it known that we, GEQRGE W. HUBBARD andScOM A. SMITH, both of Philadelphia, Pennsylvania, have invented-certainImprovementsin Grinding-Mills; end we dc hereby-declare thc'following tobe a full, clear,- "and'e'xact description of the' 'same.

-Qnr invention consists, of certain improvements, fully describedheredfter, in what are known a's portable grin'dingmills;

' In order to enable others skilled in the art tov malieanduse ourinvention, we will now proceed to describeitsco'nstruction-andoperation, reference being held to the accompanying drawing,which-forms' a part, of this specification, kind in which---' i Figure 1is a vertical section of our-improved grinding-mm. Figure 2the same,showing the sever-s1 parts detached from each other. 7 Figure 3 atransversesection on the line 1-2, fig. 1. Figure;4 anexterioi: iriew ofthe burr; and

i, I Figure 5 a perspective .view of pert of the fly-wheel.

Similar le'tter'srefer to similar parts throii'ghout the severnl-yiews.I

IA. is u'hor'izoutsl spindle, secured to or forminga pert of which is adish, 'a,huving a bevelled edge, sdnpted to the open end of theconicolburr B, to which the said disk-is confined by a suitablenumberoffset-screws, b,

.the burn being fitted snugly st one end tothe spindle. D is thetapering shell of the mill, and. is confined between-the front plate Eand rear plots F, in which plates the spindle A turns, the two platesbeing connected together-by bolts e, which also-serve to confine thehose-plate G tolthe plates, thesaid base being secui-ed'to-e platform ortable, H, or to the" top of the box whichcontsins the bolting-nppara-tusEorming a part of the plateF is the frame E, which serves to support'the platform- I, into the under siddof which is fitted a projection onthe upper end-of the curred arm J, the lowerend of the latter restingonthe Bshell D, and being fitted between andsecured to the plates EandF, and the channel e formed on one side of'the arm communicating withan'openingf, in the shell. One end of a shoe, 7', is connected bys'screw-rod, m, nn'dnut m'to'the arm J, and

by a screw-rod, n, and nut it to the platform I, the opposite end of-theshoe being hinged toe. .hlock, K, which is arranged to slide beneath'theplatform'Land which is-actedupon by a spring, p. The spindle ismaintained ,in its proper longitudinal position in one direction by acollar, 11, hearingagainst is projection on the plate E,

and in the opposite direction by the hub in of the-fly-wheel MQ I As thespindle A, 'withiits'burr, is caused to revolve, the grain falls fromthe hopper-into the shoe 7', which is agitated by projections soon thefiy-wh'eel striking the block K. From the shoe the-grain falls into thechannel 2 of the arm J, and passes downthe same-intothe openingf of'theshell, to be ground by thecombined action of the teeth of the luttera'nd those on the burr, and finally posses oil in-a-trit-uratedconditi'outhrough a spout, y, to the holt.

There are several peculiar features in. our improved mill, which we willnow roceeds) describe. p

The first, and perhaps the most important, feature is the constructingof the shell'end' 'burrjofmsllesble cast iron, case-hardened. The burr Bis first cast with appropriate teeth on it, then annealed or madeinalles'ble then turned (if necessary) inside for the reception of thedisk a, and bored to fit the spindle, and subsequently case-hardened,so" that its teeth partake of the chat-meterv of hardened steel. Beforethe casehardening, how ever, and while the dish a is in its place invtheburr, n sinooth portion, a", tigf'4, is turned on'the outer surface ofthe some, near the large-end for a purpose which will be renderedapparent hereafter;

During the above-mentioned processes of annealing andcase-hardening,which take place in the absence 'of the disk, the burr isapt to become warped towards its open end, By i'einser'ting the dish a,however, and tightening the same in its place, thehurr is not onlyrestored to its proper circular form, but'the turned portion a must heconcentric withthe'disk and spindle. I p

' In like nianner the shell D is first cast with'appropriate internalteeth, then rendered malleable, and afterwards casehardened, after whichthe large end, which had heen'previously'turn-ed and fitted into acircular recess more [in the plate E, is now driven into the same,sothat the shell is freed from all distortions which itmay have acquiredduring the annealing and case-hardening processes. The plate F is newapplied to the=small end of the shell, and secured to the plate E.

i It will be understood that the modes described of rendering the burnor shell true, are applicable to mills which have burrs or shells madesimply o'i' cast; iron, or other metal which is liable to becomedistorted with or without being case-hardened. I

It will be observed that there is a-hole; z", made'in one side of the-mill,,in the present instance, by cutting away the flange of the plateF. if, on looking through this hole, it be observed} that the spacebetween the end of the burr and plate F is being filled up; or nearlyso, it is a warning to the attendant to adjust thofeed-apparatus andreduce the supplyof grain. Inhand-mills this is. of great advantnge; asit enable the operator to work the mill at a uniform speed, and-toregulate the amount of grain ground, s'othat it shall be commensuratewith the strength which he is capable of exerting. i

Another feature of our improvements is the mode of maintaining'the burrin its proper position-within the shell." In'ordinary grinding-mills theburr is forced into the shell by a screw actingbn one end of thespindle,

so that'its duty is limited to the preventing of the burr from movingbackwards, no precaution being taken-toprevent it from coming in contactwith the shell and-injuring the grindingsurfaceswof both, should -aproper supply of grain be wantin g in the mill, or shouldan unduelongitudinal strain beimparted to the spindle'rhil it is being driven. v

These objections are obviated-by the adjustable collar won the spindleat i one end of the mill, and by the hub of the fiy-wheel,'rvhichacts-asan adjl'istable collaryon the spindle at the opposite end ofthe'millIndependently of the duty whichthese col'lars perform, of maintainingthe burr in its proper position and I preventing the grinding surfacesfrom coming in contact, they aiford facilities for making on the shaftmarks,

which, in connection with the collars, will serve'as-guides torestorethe burr to its proper position in the shell after it has been changed.Graduated marks maybe made on'the' shaft, to indicate the properadjustment for difl'erent degrees of finenessin grinding, 1

We claim as ourin'vention, and desire to secure by Letters Patent-- 1.The lever B, combined with and trued by the disk'a, substantially asdescribed I 2. Jlhe shell 1), with its inclined edge adapted to theplate E, substantially as set forth. I 3. The spindle Awith itsburr,whenconfi ned in its place within'the shell by two adjustablecollars arranged. upon the'spindle, as specified. I Intestimony whereof,wehavesigned our names to this specification in the presence oftwo-subscribing witnesses. GEO. W. HUBBARD,-

SCOTT A. SMITH.

'Witness'em.

ALrnnn B. Srovnnn, A. B. Wmurs

